In June of 2013, journalist Glenn Greenwald unveiled to the world that an American had leaked documents from a secretive U.S. defense agency, the National Security Agency. The leaker was a man named Edward Snowden, who had worked at the NSA for four years and was hired through a contractor.

The stories published by The Guardian revealed practices never before revealed publicly about the America's surveillance programs, such as a metadata collection program on Americans' phones and the revelation that the NSA may have spied on world leaders.

After Snowden fled the U.S. an international manhunt began and it captured the attention of the world. Snowden taped an on camera interview with Greenwald and colleague Laura Poitras to reveal himself to the world as a self-described "whistleblower."

Glenn Greenwald's new book “No Place to Hide,” describes the behind-the-scenes story of how the journalist and his colleague Ms. Poitras met Mr. Snowden and what took place after. Greenwald spoke to Anderson about the book.

Journalist Glenn Greenwald's reporting on the documents leaked by Edward Snowden broke the story of the NSA's mass surveillance programs. Critics including House Intelligence Committee Chairman Mike Rogers have suggested Greenwald's actions may have been criminal. Greenwald lives in Brazil and has not been back to the U.S. since the story broke. But he talks to Anderson about why that might change.

President Obama delivered a 45-minute speech today laying changes for the NSA. Some reforms will be immediate, others will take effect over time. What does this mean for your privacy, and the government's ability to prevent terror attacks? Jim Sciutto breaks down some of the big changes for the NSA.

There is little doubt today's speech would not have happened without Edward Snowden's leaks. Anderson discussed all of this with journalist Glenn Greenwald who published many of those leaks, and Andy Card who served as Chief of Staff in the George W. Bush administration.

A new study from the non-partisan New America Foundation refutes claims by the government that the NSA's collection of phone records has foiled dozens of terror threats. The AC360 Later panel debates the impact that NSA spying really has on terrorism.

A federal judge ruled that the NSA operation which collects numbers from all our phones is legal. This comes one week after another federal judge reached the exact opposite conclusion. So what happens now, and who has the final decision? CNN’s Senior Legal Analyst Jeffrey Toobin has the answers.

There’s a new call for setting stricter limits on the NSA's mass-surveillance program. This time it's coming from the panel appointed by the White House to help restore public confidence. In it's report the panel says the NSA should no longer maintain massive databases of phone records on each and every American. This comes after Monday's ruling by a federal judge that this type of spying likely violates the Fourth Amendment. Chief National Security Correspondent Jim Sciutto has the latest.

Anderson discusses all of this with investigative journalist Glenn Greenwald, who broke the Snowden story, and Senior Legal Analyst Jeffrey Toobin.

A judge ruled today that the NSA program that can collect phone records on each and every call that Americans make is likely unconstitutional. It's a program that was a top secret until Edward Snowden revealed it. Could this mean Snowden now deserves amnesty? Anderson discussed this with investigative journalist Glenn Greenwald and Senior Legal Analyst Jeffrey Toobin.

Director of National Intelligence James Clapper appeared before the House Intelligence Committee today and admitted America has been spying on close allies for years, but also claims that U.S. allies absolutely spy on American leaders. After today's testimony journalist Glenn Greenwald spoke to Anderson and challenged claims that leaks he published from Edward Snowden harmed America's fight against terror.

We are now learning the NSA surveillance program that targeted world leaders’ phones may date back to 2002. The Wall Street Journal is reporting President Obama did not learn about it until last summer. Now Senate Intelligence Committee Chair Dianne Feinstein is calling this "a big problem" and wants a full review of all of America's intelligence programs. Jim Sciutto has the latest.

The Obama administration is doing damage control after allegations the NSA may have spied on world leaders. This is just the latest revelation published by the Guardian from documents leaked by Edward Snowden. Now German Chancellor Angela Merkel and French President Francois Hollande are talking about resetting the ground rules when it comes to surveillance. Jim Sciutto has the latest.